Drying apparatus



J. i=ARAsEY July 2/1929.

' DRYING APPARATUS- Filed March' 28, 1928 s Sheets-Shet 1 y 2, 1929- JQFARASEY 1,719,603

DRYING APPARATUS Filed March 28, 1928 's Sheets-Shet 2 F lGr' 2 arm QWW J. FARASEY DRYING APPARATUS July 2, 1929.

Filed March 28, 1928 5 Sheets-Sheet I attouwqd J Patented July 2, 1929.

UNITED STATES JAMES FARASEY,-.OF CLEVELAND, DH'IO.

DRYING APPARATUS.

Application filed March 28, 1928. Serial No. 265,251.

This invention relates to a drying apparatus of the type having a rotating approximately horizontal drum through which the material travels and into which externally heated gases discharge. The primary object of the invention is to so arrange the heating means as to eii'ectively dry the ma terial without subjecting the shell to undue heat in any particular region.

In machines of the type mentioned, it is customary to equip the shell with inwardly extending elbows open to .the exterior, and to provide a fire box beneath the shell from which the products of combustion or some of them may pass through. thehollow elbows to the interior of the shell. It has also been proposed to inject heat, preferably from an oil burner, into the open or discharge end of the shell. I propose to combine both methods of heating with a further heating feature of carrying some of the products of combustion of the primary heater into the discharge end of the shell, whereby the ma terial within the shell may be very effectively heated without the shell being subjected to undue heat in any particular region. The means by which I effect this is illustrated in the drawings hereof, and hereinafter more fully described, and the essential novel characteristics are set out inthe claims.

In the drawings, Fig. 1 is a side elevation of a complete drying apparatus embodying my invention; Fig. 2 is a vertical longitudinal central section of the apparatus, on a larger scale; Figs. 3 and 4: are vertical crosssections on the lines 3--3 and 1- 1 on Fig.

2, these views in each case looking toward the right of Fig. 2..

In each of the views, indicates a hollow drum or shell nearly horizontal, but slightly inclined downwardly toward the dis charge end, that is toward the right .in Figs. 1 and 8. This shell is shown as provided on its exterior with supporting rings 11 and 12, which rest on sets of rollers 13 and 1, 1 supported on a suitable frame. This frame may include longitudinal side members 15 and suitable cross members and may be supported on wheels 17. The frame may also carry protecting jackets 18 and '19 over the shell. These jackets may have vertical side walls and a horizontal top, as indicated in Fig. 3, and be-provided with transverse end plates having circular openings, through which the shell extends.

The-shell v 10 is shown as equipped withean external gear 20 meshing with suitable gearing 21 which connects with suitable power ior slowly rotating the shell. An inclined entrance spout 25 leads into the left hand driven endless conveyor 31 and dropped over into a chute 32 leading downwardly to a suitable screen whlch may be enclosed within the casing 38, Fig. 1, from whence the screened material may pass into a bin 34.

The screen and bin may ifdesired be constructed in accordance with my Patent No. 1,587,291 and thus adapted to divide the material into d.il'l'erentgrades within the bin 34. The material, as desired, may be discharged from the bin into a weighing hopper' 37 and thence pass to a grinding mill 38. I

In such drier the rotating drum is usually provided with longitudinal inwardlyextencL ing angle slats 10 which serve to lift the .material continually toward the top of the drum .and then allow it to drop. As the drum is slightly inclined, this lifting and dropping causes the material to travel in a helical course from the entrance to the dis charge end of the drum.

The drum shown carries a number of\liol low elbows securedto the shell in various positions, preferably in a spiral course about the drum, each elbow leaving the shell wall radially and then turning toward the entrance end of theshell terminating parallel with the axis. Each elbow may have a flanged shield 46 across it beyond its dis charge end, which provides an annular discharge passageway from the-elbow as shown in Fig. 2, but prevents the material passing into the elbow. These longitudinal. slats and shielding elbows are well known in this art.

My invention is well adapted for a drier constructed and arranged substantially as above described. lVith such a drying drum I proposeto supply heat to the interior su'lliciently to drythe material, and direct such heat in amanner to act effectively on all of the material, without subjecting the shellto undue heat in any region. After leaving the shell, the cooled products of combustion pass into a collecting chamber from which they pass up a stack 51 urged by a fan 52.

In my invention I have arranged the heating means with special reference to utilizing the heat and the products of combustion within the shell, thus drying the material, and delivering such products at a comparatively low temperature to the stack. By absorbing as much heat as possible by the material within the shell, I increase the ellicienoy of the operation and reduce the deterioration. of the parts adjacent the stack, as for-instance the discharge fan. I accomplish this even distribution of heat by the following means.

Beneath the shell is a lire box having a suitable grate for burning coal, indicated at 61. This fuel may be inserted in the lire box through side openings normally closed by doors 63. Some of the heat from such burning fuel passes through the elbows 45, which it will be noticed are in the region directly above the fuel, whereby such heat directly enters the shell. The fuel is in front of a suitable bridge wall 65. Above this wall is a transverse heat insulated frame portion 66 which carries the set of rollers 14; upon which the drum ring 12 rests.

Between the bridge wall and the support (36 is a rearwardly extending pass geway through which products of combus on from the fuel. Such products of combustion cannot pass through the wall of the shell, as there are no openings or elbows be yond the ring 12, but they pass to the extreme end of the shell into a housing which may comprise an overhanging portion of the jacket 19, adjacent the shell discharge, and thence pass into the extreme end of the shell. A suitable door 68 allows access to the region of the bridge wall, to enable its periodic repair, whileia door 69 is provided to the combustion space beyond the bridge wall, for cleaning out purposes.

The products of combustion from the fuel 61 accordingly have two paths of exit. Part of the products pass through the elbows into the interior of the shell and meet the dampest material, thus giving it an initial drying as it passes toward the discharge end. After leaving the region of the elbows, the material which has been somewhat dried comes into the region of the shell beyond the support (36 and there receives those products of combustion which have passed into the shell through its right hand end.

To prevent the shell becoming chilled at the exposed intermediate region between the jackets 18 and 19, and prevent undue radiation of heat from the shell in this region, I mount the ring 12 on the exterior of a short cylindrical sleeve 70 which is spaced outside of the shell, but supported by it by suitable intermediate brackets 71, Fig. 4-. The sleeve 70 is long enough to reach from the region within the jacket 18 to that within the jacket 19, and thus this sleeve provides a flue from one jacket to the other. For practical purposes, this provides a continuous jacketing for nearly the entire length of the shell.

In order to dry the material most effectively, I arrange to supplement the heat which comes from the fuel 61 into the shell by a direct discharge of heat into the open end of the shell, preferably from an oil burner 75. This burner is shown in Figs. 1 and 2 as extending into an interior of a conical shield 76 which allows it to dcllect, so that the burning fuel and the hot products of combustion may reach the material in the end portion of the shell. This heat supplementing the heat from the fuel. 61 serves to render the material in the discharge portion of the shell perfectly dry, so that when it passes out of the shell into the chute 28, it is ready for grading and storing.

3y carrying the heat from the fuel (51 partly to the end of the shell and then into the interior of the shell instead of carrying it all through the elbows 4:5, I relieve the portion of the shell innnediately above the lire from some of the intense heat of the fire, whereby a longer life is obtained for the shell. Furthermore by carrying some of the heat from the fire 61 into the discharge portion 'of the shell and supplementing it with the oil heat, I obtain an intense heat on the material where it most needed, namely in the linal drying operation, without subjecting the metal of-the shell itself to such heat, the material acting to protect the shell from the interior heat.

Furthermore, by connecting the open end of the shell with the discharge from the :[ire box (it), I am enabled to make the lire draft caused by the fan 52 pass through the entire length of the drum and this tends to carry forward the hot gases injected by the oil burner 70. It results therefore, that the heat provided. by the fire 61 and the oil burner 70 is distributed through the material, giving a comparatively light heat at the discharge end, which heat is gradually absorbed by the material. The result that when the products of combustion reach the stack, they have been greatly reduced, thus reducing the heat loss, as well as giving a longer life to the fan and adjacent parts.

I claim 1* v 1. In a machine of the character described, the combination of a rotary approximately horizontal shell, a fire box extending for a considerable region beneath the shell, a bridge wall dividing the fire box, a fire door leading to the space in the fire box in front of the bridge wall, passageways into the interior of the shell directly above this portion of the fire box, the shell above the portion of the fire box on the other side of the bridge wall being imperforate, a passageway by which the products of combustion from the latter portion of the fire box may pass over the end of the shell into the interior, a transverse support extending crosswise of the upper portion of the fire box above the bridge wall, a pair of rings carried by the drum, wheels on which said rings rest, one set of wheels being in front of the fire box and the other set carried by said transverse support, and a pair of independent jackets for the shell, one over the region between the rings and the other over the region between the rear ring and the end of the shell.

2. In a drying apparatus, the combination of an approximatey horizontal rotary shell through which the material to be dried may travel, said shell being provided with an intermediately located external supporting ring, and a pair of jackets extending about the shell respectively in front of and beyond the ring, and means providing a flue within the ring from one jacket space to the other.

3. In a drying apparatus, the combination of an approximately horizontal rotary shell through which the material to be dried may travel, said shell being provided with an intermediately located external supporting ring, a cylindrical sleeve surrounding the shell and spaced from it and carried by it, the ring being mounted on said sleeve, and a pair of jackets extending about the shell respectively in front of and beyond the ring, the spaced sleeve serving to make a flue from one jacket space to the other.

4. The combination of an approximately horizontal rotary shell through which material to be dried may travel, a comparatively short cylindrical sleeve surrounding the shell in an intermediate region spaced from it and connected with it, a pair of jackets extending about the shell, the sleeve serving to substantially connect said ackets to make a flue about the shell from one jacket to the other, a supporting ring mounted on said sleeve between the jackets, a transverse frame support beneath the sleeve having wheels on which the ring rests, and a the box beneath the shell hav-' ing a grate in front of said transverse support, and a combustion chamber at the rear thereof, and a heat passageway beneath the support from the space above the grate to the combustion chamber.

5. In a drying apparatus, the combination of an approximately horizontal rotary shell through which the material to be dried may travel, said shell being provided with heat passageways through the shell to the interior, said passageways beingw grouped in one region of the shell, the shell having an impervious region beyond the group of passageways, two jackets respectively over the pervious and the impervious sections of the shell, a supporting ring for the shell between said jackets, and a sleeve carried by the shell and spaced about it and extending substantially from one jacket to the other and supporting said ring.

6. In a drier of the class described, the combination of a rotary shell into which material may be fed, and out of which the dried material may be discharged, said shell being provided with a series of inwardly extending hollow elbows, a fire box directly beneath the shell, said fire box having an interior bridge wall, the chamber beyond the bridge wall discharging into the interior of the shell over its end, a pair of jackets respectively over the portion of the shell in front of the bridge wall and the portion behind the bridge wall, and means above the bridge wall and between the the jackets for intermediately supporting said shell, there being provision for preventing the chilling of the shell between the jackets.

7. In a drier of the class described, the combination of a rotary shell into which material may be fed, and out of which the dried material may be discharged, said shell being provided with a series of inwardly extending hollow elbows in a region adjacent the intake, the shell having an impervious wall in a region adjacent the discharge, a fire box directly beneath the shell in the region of the intake elbows and also the imperforate region and having uninterrupted communication directly with such passageways, said fire box having an interior bridge wall beyond the elbow-region, the chamber beyond the bridge wall discharging into the interior of the shell over its end.

In testimony whereof, I hereunto affix my signature.

JAMES FARASEY. 

